Im ready to install a new sonar up front on my ranger 364v, I don't have a power block up there so im going to have to run power from the battery all the way up front. What is the easiest way to run it clean and without having to pull on old wires? The boat is 18ft

Easiest is to tie on to old wire and pull the new wire through, if you are removing the old wires. Next easiest is to get a fish tape run it through then attach wires and pull back. You'll have to decided whether it is easiest to run the fish from front to rear or rear to front. On my boat, it is pretty easy to get it to run the length without hitting obstructions.

check wiring harness up front should have 2 wires with connectors on them just tied up. should be a hot and ground if they haven't been used for something else. the are also fused in the ranger fuse block